DIFFERENTIAL MICROBIAL COMMUNITY STRUCTURE AND FUNCTION ON CHIRONOMID SUBSTRATE, FRASS, AND TUBES IN RESPONSE TO FEEDING PRESSURE

Despite decades of research, our understanding of the interactions between macrobenthic and microbial communities remains imperfect at best. We employed molecular and biochemical techniques to further understand this relationship using the midge Chironomus tentans. We studied microbial community organization on three phases of artificial substrate (frass, tubes, and unutilized) after chironomid development from second instar to emergence at three levels of feeding pressure. Shifts in microbial community structure were quantified using RAPD technology to assess patterns in genetic diversity between treatments and substrate phase. Microbial community function was measured through substrate utilization and enzyme activity. These techniques allowed us to quantify differences in microbial community organization between both treatments and substrate phases and shed new light on microbial invertebrate interaction.